In this study

the effects of three types of V-shaped slit nozzles of different structures on the heat transfer of impingement quick-freezing equipment under 170-Pa and 190-Pa pressure conditions are compared by both numerical simulation and experiment. The outlet wind velocity

cross flow wind velocity and Nussel number (Nu) are investigated under different conditions. The results show that the nozzle outlet with a longerK

nozzle extension length

has a higher wind speed and more uniform flow field. However

the longer K will weaken the convective heat transfer intensity. The nozzle with a smaller angle α between the nozzle shrinking and extension sections has a lower wind speed and higher uniformity in the transverse flow direction and is less affected by the transverse flow; however

it has no obvious effect on improving the convective heat transfer intensity. When the length of the K of the V-shaped slit nozzle is 10 mm and the angle α between the nozzle contraction and extension sections is 165°

the average Nussel number and the convective heat transfer intensity are at a maximum.